Yielding barrier



March 26, 1946. E. D. sAwYER YIELDING BARRIER- Filed May 27, 194s l 2 sweets-sheet 1 uvam.)

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*fm/@infor Patented Mar. 26, 1946 UNITED STATES PATENT OFFICE 2,397,330 YIELD-ING BARRIER Emerson D. Sawyer, Chicago, Ill.

Application May 27, 1943, Serial No. 488,777

(Cl. 3.9-7 )I 3 Claims.

My invention relates to certain novel improvements in yielding barriers, and has for its principal object the provision of an improved construction of this character, which provides a more eflicient means for suspending the barrier net tautly between the columns of the. barrier structure.

A further object of this invention is to provide a novel means, both in connection with the net proper and the snubbing mechanisms within the columns, so as to obtain a taut horizontal net structure without the use of auxiliary netsuspension devices which must be replaced manually after an impact test.

- A third object is. to provide means for obtaining a taut horizontally disposed roadway network, without appreciable sag even on roadways far wider than heretofore attempted,` without the use of additional counterweight on the retrieving mechanism of the yielding barrier.

Yielding barriers for bridge and roadway pro tection have been designed to conform to standard column sizes and dimensions, depending on the strength of structure required. These standardized designs, due to architectural limitations, do not permit of readily changing the general features of the barrier construction, except for the 4length of the portal framing, which depends on the width of the roadway. Hence this new invention should naturally utilize features which fit in readily with the general barrier mechanism. This is a further object of my present invention.

Other objects will appear hereinafter.

The invention consists in the combination and arrangement of parts hereinafter described and claimed. Y

'I'he invention will be best understood by reference to the accompanying drawings forming a part of this specification, and in which,

Figure 1 is a general partial elevational view of the barrier structure, showing ther net in full outline in its lowered position anda dotted outline in its raised position, as well as showing a possible extended position of the net from its lowered position.

Fig. 2 is a sectional elevation taken on the line A-A of Fig. 1, showing the motor column of the barrier, omitting portal section.

Fig. 3 is a sectional view taken onv the linev B-B oi Fig. 1, showing the lowered net in both its normal position across the roadway and in a possible extended position.

Fig. 4 is an enlarged elevational view of the end of the net as attached to the drum box which travels within ther column. i

relation of the payout cable to the recoil cable,

with the net slightly extended from its normal position across theroadway. Thisview is also taken on line D-D of Fig. 5.

Fig. 8 is an outline view showing the relation of parts shown in Fig. 6. This View shows the relation. of the payout cable to the recoil cable, with the net generously extended from its normal position across the roadway. Thisv view is also taken on line D-D of Fig. 5.

Fig. '9 is a partial front view of the cable drum within the drum box and taken on the line E-E of Fig. 4.

Yielding barrier devices generally consist of the parts as best shown in Figs. 1 and 2; namely, the numeral I indicates thecolumn or standard, one of which is located on each side of the roadway; numeral 2 indicates the portal framed between the columns I and located substantially above the roadway level. Within the column l on each side of the roadway is drum box 3, mounted to roll vertically. The network of the barrierl which stretchesy across the roadway is comprised of top cable4 4, bottom cable 5, central cable 6, catenary suspension cable 1, vertical strips 38, rigid end bars 45, and diagonal cables 48. The cable net is attached to the mechanism within the drum box 3 by means of payout cables 8 and 9.

The general mechanism used in raising and lowering the net across the `roadway consists of a motor I9, driving mechanism 20, which is generally a chain device, speed reducer I8, transmission chain I1, tail sprocket I6, head sprocket I4, raising and lowering chain I5, and synchronizing shaft' II, which shaft II and keyed-on sprocket IB and I4 are the means of raising and lowering the mechanism in box 3 and its attached partsA uniformly in each of the two columns I, although the motor-driving mechanism exists in onlyV one column.

Now` referring more particularly to Fig. 3, as well as Fig. 1, the numeral 8a indicates the top payout cableA in an extended position. The numeral 4a indicates the top cable of the net in anl extended position. These extended positions of 2 c the net cables and payout cables are produced by an impact test against the net, and after the impact vehicle has been backed away from the net Vthe net cables would assume positions such as shown in dotted outline at 4a and 5a. Now referring to Figs. 1 and 2 again, the numeral I3 indicates the iiexible cable connection known as the balance cable, orretrieving cable. This cable I3 passes over sheave I2, which is mounted to turn freely on shaft I I, and then runs downwardly and under sheave 49, which supports the counterweight Ida. The cable I3 then runs up to a becket 5'0. The cable I3, after entering the box 3, is attached on a drum 22 in groove 25, as best shown in Fig. '5. Thus due to the cable I3 and the suspended counterweight Illa, the drum box 3 and the attached net can be made to move from a down to an up position by means of the motor I9 with a minimum effort, due to the suspended balance condition of the parts within column I.

The counterweight Illa is shown in its normally raised position, with the drum box in position 3a. It will be noted that counterweight Illa is hanging in the bight of cable I3 and drum box 3a is hanging on the single strand of cable I3, which permits box 3 to. travel twice the distance of counterweight Illa. Counterweight Illa shown in its normally up position, is permitted further abnormal upward travel toward becket 50 for the purpose of serving as the means for retrieving the runo'ut net.

Now referring more particularly to Fig. 5. Cable I3 enters the top of box 3, passing into the vring to Fig.'4, when the box 3 is lowered into position 3a, the lever 29 is depressed into position 29a, due to being rolled in behind a cam track 30 attached to the column I. This is to afford the Ysnubbing action or braking action made effective through the leverage 28 and the brake band 27 onthe drum 26. After the impacting vehicle has been freed from the net, and the box 3 is raised slightly above its lowered position 3a, this allows the lever 29 to assume its disengaged position groove 25, and Vdownward and into rounded edge slot 31 formed in one wall of the groove 25, and then on through chamfered opening 35 in the drum 26, Yand is secured at its vend by clamp 36. This is also brought out in Figs. 6 and 9. The payout cable 8 and its counterpart, lower payout cable 9,`enter. through the front of box 3 and are Wound on the drum 22 within the box, cable 8 on'groove 24, and cable 9 on groove 23. Referring to Fig. 6, cable 8 is shown wound about four times around in groove 24, and dead-ended in a radialsocket 33, thus providing storage length for the payout cable. On previous barrier constructionsV the cable I3 was also dead-ended in its'cable groove in a radial socket. In the present construction the cable I3 is dead-ended farther away from the center of shaft 2I than formerly was the case. The object of this change in constructionis to afford a greater leverage due to the pull of cable I3 upward through the top of box 3, as

A induced by the counterweight Ilia, and hence able tov provide a greater rotative retrieving eiort when cable 8 is fully wound on drum groove 24. The box 3 when in its lowered position 3a, as shown in Fig. l, and assuming that the net is normally across the roadway, suspends the counterweight I 0a in its normally raised position, due to the cable I3. With the parts in these relative positions, and assumingthat the net is hlt, then the payout cable 8 is run out through .the front of the box, and the cable I3 is coiled Vonto the drum 22 inits groove 25, and counterweight lila is raised to an abnormal up position. Cable 8 is wound counter-clockwise aroundthe drum and cable i3 is wound clockwise around the drum. As the cable I3'tends to wind in the groove25 it first assumes a snug-fit position in rounded slot 31, as best indicated in outline in Fig. 7. Then as the cable I3 is furthercoiled on its drum 22 in groove 25, it will assume the position shown in Fig. 8. It is here noted that'as shown in Fig. 8,k

the cable I3 is Venabled to coil itself one turnY onn from behind the cam track 30. With this condition existing, the cable I3, due to its attached counterweight ma, is free toy unwind from the drum 22 in groove 25. This in turn recoils the cable 3 into its groove 24, as well as. cable 9 into groove23. And this recoilng action gains momentum generally, as gravity pulls on counterweight Illa, except at the nal portion of the recoiling, where the net is just being lifted into a taut position; then there is anecessity for additional counterweight pull. This is best described in the transition from the position ofcable I3, as shown in Fig. 7, back to its position as shown in Fig. 6. VIts dead-end anchorage increases the eifective pull of the counterweight, due to the increasing leverage arm obtained by moving the Socket 35 of Fig. 7 into its position as shown in y Fig. 6. The counterweight, when being acted on by gravity, downwardly, has a tendency to speed its motion, and this increased speed of motion, together with the increased leverage as above described, is sufficient to pull the net tautly back into a horizontal position. Referring to Fig. 4, stop lugs43 and 41 are placed on the payout cables 8 and 9 respectively, Vso as to check the Vrecoil of the cables 8 and 9 at the proper position so that the net will beoriented in its proper position between the two columns I, even in case the4 recoil mechanism in one column speeds ahead of the recoil mechanism in the other column.

' With extra wide roadways it has been found impractical to have the counterweights in the columns of suflicient size to return the net to its proper taut position, even with the abovedescribed improved recoil device. In order to obviate the possibility of having a sagging net unof the net. The cable 7 passes through loops 4E)v in the stiffener bars 39 of vertical strips 38, and this cable 'I is vso threaded along the net that it will pass through loops 49 near the center of the net at a point above the center of gravity of the net structure. This is at the-lowest point of the catenary. The slight stiffness4 of. the barsv 39 maintains the suspension of the cable 4 in a taut position above the catenary cable 1, although the tensile pull which sustains the whole net structure can be thrown mainly on the catenary cable 1, transmitted through the end bars 45 and through the payout cable 8 into the counterweight suspension mechanism. Since the .sustaining suspension pull required to suspend the net in a taut position varies inversely as the distance measured as the sag of the suspending member, it is readily seen th'at this adjustable catenary construction affords a very novel means for producing a taut net on fairly wide roadways, without additional counterweight being necessary. The adjustable eye-bolts 44 are so formed that the front elliptical section 4I` slides through an elliptical opening 42 in the lugs 43, which are attached to the end bars 45. This allows adjust-` ment of the catenary cable Without any tendency to rotate the same. These non-rotatable eyebolts 44 permit of adjustment of the distribution of the tensile pull taken by cable '1, except for the slight tension left in the cable 4 and cable 5. The loops 40 through which the cable 1 passes along the net, are made just strong enough to serve as local suspension members attached to the cable 1, or rather, mounted on the cable 1, but in case of impact these loops 40 can be ruptured readily so lthat none of the load-or at least practically none of the load-of impact will be carried by the cable 1, but instead by the cables 4 and 5.

It is seen from the foregoing description of this invention that the eiiiciency, general appearance, and application of yielding barrier devices are enhanced thereby.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modication Without departing from the spirit of the invention. I therefore do not wish to be limited to the precise detail of construction set forth, but desire to avail myself of such variation and modification as come within the scope of the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination With a barrier net and payout members operatively connected therewith and wound upon a retrieving drum, of a retrieving cable having its extreme end anchored to said drum at a point radially beyond the operative periphery thereof and arranged to wind upon the periphery of said drum as thepayout members pay out; and means for exerting tension on said retrieving cable to unwind it from said drum and thereby recoil said payout members thereon.

2. The construction specified in claim 1 in which the retrieving cable is actuated by a counterweight operatively connected therewith.

3, The construction specified in claim 1 in which the retrieving drum is flanged, and said ange is provided With a seating recess in which the end of the retrieving cable is anchored, thereby permitting the cable to wind spirally one turn on top of the other.

EMERSON D. SAWYER. 

